A Yemeni pro-government fighter sits with his weapon on the back of a pick-up truck on the front line against Houthi rebels, outside of Sanaa, on January 31, 2018. Glen Carey / Bloomberg

A senior Houthi official has called on high-ranking rebels to step up reconciliation efforts with followers of Ali Abdullah Saleh after hundreds of commanders and fighters loyal to the former Yemeni president withdrew from rebel frontlines following his murder.

The Houthis and Saleh formed an alliance in 2014 against the internationally recognised government of president Abdrabu Mansur Hadi. But this partnership broke down last year with clashes breaking out between the two sides that culminated in the killing of Saleh by Houthi fighters in December.

Speaking at a meeting of senior Houthi officials on Wednesday, Saleh Al Samad, president of the so-called "Supreme Political Council" that runs Sanaa and other rebel-held areas, expressed his concern over the defection of "large numbers" of Saleh loyalists.

He called on Houthi officials in all rebel-held areas to engage in reconciliation talks with the ex-president's followers, the Houthi-run Saba news agency reported.

Thousands of renegade members of Yemen's security forces fought alongside the Houthis before Saleh's killing. But since then more than 1,500 have switched sides to fight with Hadi-aligned forces, according to the spokesman of pro-government forces operating on Yemen's western coast, Colonel Naser Al Redhami.

Mr Al Samad also asked rebel officials to release members of Saleh's General People's Congress party who were imprisoned by the Houthis in a crackdown following the former president's death. He did not mention the fate of Saleh's detained family members, however.

His call for reconciliation between the two sides comes as Houthi forces in Al Hodeidah, Sada, Al Jawf and Taez fronts face severely depleted numbers amid both defections and battlefield deaths and arrests.

The rebels are locked in fierce battles with forces aligned to president Hadi, whose government was forced to relocate to the southern city of Aden after the Houthis captured Sanaa in September 2014. A Saudi-led military coalition is fighting alongside these pro-government forces to restore Mr Hadi to power.

Pro-government forces are tightening their grip around the rebel-held port city of Al Hodeidah, which has been the main route through which the Houthis have smuggled in weapons and fuel from outside Yemen. The strategic city's recapture by pro-government forces would mark a huge victory for Mr Hadi's government.

Col Al Redhami said pro-government forces were making extensive preparations to open up a new front in Al Hodeidah in the "near future", aimed at retaking the historical city of Zabeed, near the provincial capital. This effort will include forces led by Major General Tariq Mohammed Abdullah, a nephew of ex-president Saleh who switched sides in Yemen's war following his uncle's death.